Before installing a newer version of ITCH, find the existing ITCH executable (.exe file) on your computer and rename it. Renaming it after the version number is a useful way of identifying each version - especially if you plan on installing multiple versions. For example; if you currently have 2.2 installed, rename ITCH.exe to ITCH_2.2.exe
(ITCH.exe is located by default in C:\Program files\Serato\ITCH)
Now, when you install the new version, the old executable will not be deleted, and you can choose which you want to run by going into that folder and double clicking on the executable. You could also create shortcuts on your desktop for each version if you wanted to.
(Right click on each .exe, choose Send To > (Desktop create shortcut))
Before installing a newer version of ITCH, go to your applications folder, and rename the existing ITCH application file. For example; if you currently have 2.2 installed, rename ITCH to ITCH_2.2
Now, when you install the new version, the old application will not be deleted. You can choose which you want to run by clicking on the applicable version in the applications folder. You can drag any number of these applications to your dock for quick launching. (The dock will not automatically update with a new installation)
Warning: It is not advisable to run more than one instance of ITCH at one time. Doing so could cause problems with your ITCH database.